Illumination device

ABSTRACT

An illumination device includes a base, a light-emitting module, a first layer, and a second layer. The light-emitting module is disposed on the base for generating a progressive-type light-emitting intensity. The first layer encapsulates the light-emitting module. The second layer encloses the first layer. The second layer has a progressive-type thickness corresponding to the progressive-type light-emitting intensity, and both the progressive-type light-emitting intensity and the progressive-type thickness are decreased or increased gradually, thus the progressive-type light-emitting intensity can be transformed into the same light-emitting intensity through the progressive-type thickness of the second layer.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. application Ser. No.12/849,491, filed on Aug. 3, 2010 and entitled “photoelectricsemiconductor device capable of generating uniform compound lights”,which is a continuation application of U.S. application Ser. No.12/401,620, filed on Mar. 11, 2009, now U.S. Pat. No. 7,888,698, andentitled “photoelectric semiconductor device capable of generatinguniform compound lights”, the entire disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The instant disclosure relates to an illumination device, and moreparticularly, to an illumination device with a progressive-type designfor generating a uniform light-emitting source having the samelight-emitting intensity.

2. Description of Related Art

Light-emitting diode (LED) has been outstanding in energy-savinglighting with its features of small size, long device lifetime, highdurability, environmental friendliness, and low power consumption. Ofall the LEDs, white light LED (or LED with compound lights) combines twoor more monochromatic lights and has been widely used in indicatinglamps and display devices in information technology, communications, andconsumer electronics products. In addition to improving the lightemission efficiency, the unevenness of lights from the LED also requiresan urgent solution in the study of compound LED and lamp.

To solve the unevenness issue, a prior art with coating phosphor ontothe surface of the LED chip has been proposed. However, another problem,such as limited chip type, high cost, low light emission efficiency ornarrow light angle is encountered.

SUMMARY OF THE INVENTION

One aspect of the instant disclosure relates to an illumination devicefor generating a uniform light-emitting source having the samelight-emitting intensity.

One of the embodiments of the instant disclosure provides anillumination device, comprising: a base, a light-emitting module, afirst layer, and a second layer. The light-emitting module is disposedon the base for generating a progressive-type light-emitting intensity.The first layer encapsulates the light-emitting module. The second layerencloses the first layer, wherein the second layer has aprogressive-type thickness corresponding to the progressive-typelight-emitting intensity, both the progressive-type light-emittingintensity and the progressive-type thickness are decreased or increasedgradually, and the progressive-type light-emitting intensity istransformed into the same light-emitting intensity through theprogressive-type thickness of the second layer.

Another one of the embodiments of the instant disclosure provides anillumination device, comprising: a base, a light-emitting module, afirst layer, and a second layer. The light-emitting module is disposedon the base for generating a progressive-type light-emitting intensity.The first layer encapsulates the light-emitting module. The second layerencloses the first layer and having a phosphor powder, wherein thesecond layer has a progressive-type concentration of the phosphor powdercorresponding to the progressive-type light-emitting intensity, both theprogressive-type light-emitting intensity and the progressive-typeconcentration of the phosphor powder are decreased or increasedgradually, and the progressive-type light-emitting intensity istransformed into the same light-emitting intensity through theprogressive-type concentration of the phosphor powder in the secondlayer.

Yet another one of the embodiments of the instant disclosure provides anillumination device, comprising: a base, a light-emitting module, afirst layer, and a second layer. The light-emitting module is disposedon the base and electrically connected to the base for generating aprogressive-type light-emitting intensity. The first layer encapsulatesthe light-emitting module. The second layer encloses the first layer andhas a phosphor powder with a plurality of phosphor particles, whereinthe second layer has a progressive-type particle radius of the phosphorpowder corresponding to the progressive-type light-emitting intensity,the progressive-type light-emitting intensity varies inversely as theprogressive-type particle radius of the phosphor powder, and theprogressive-type light-emitting intensity is transformed into the samelight-emitting intensity through the progressive-type particle radius ofthe phosphor powder in the second layer.

Yet further another one of the embodiments of the instant disclosureprovides an illumination device, comprising: a base, a light-emittingmodule, an encapsulation layer, and a phosphor layer. The light-emittingmodule includes at least one optoelectronic component disposed on thebase for generating a first light having a progressive-typelight-emitting intensity. The encapsulation layer encapsulates the atleast one optoelectronic component. The phosphor layer with a phosphorpowder encloses the encapsulation layer and has a progressive-typestructure in correlation with the progressive-type light-emittingintensity, wherein the progressive-type structure is one of aprogressive-type thickness, a progressive-type concentration of thephosphor powder, and a progressive-type particle radius of the phosphorpowder, and the first light passes through the phosphor layer togenerate a second light having the same light-emitting intensity.

These and other objectives of the instant disclosure will no doubtbecome obvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an illustration of the illumination device using at least oneoptoelectronic component according to the first exemplary embodiment ofthe instant disclosure.

FIG. 1B is an illustration of the illumination device using threeoptoelectronic components according to the first exemplary embodiment ofthe instant disclosure.

FIG. 1C is an illustration of the first, the second, and the thirdexemplary embodiments of the illumination device using at least oneoffset optoelectronic component separated from an imaginaryoptoelectronic component according to the instant disclosure.

FIG. 1D is an illustration of the illumination device applied as a lamptube according to the first exemplary embodiment of the instantdisclosure.

FIG. 1E is an illustration of the illumination device applied as a lampbulb according to the first exemplary embodiment of the instantdisclosure.

FIG. 2A is an illustration of the illumination device using at least oneoptoelectronic component according to the second exemplary embodiment ofthe instant disclosure.

FIG. 2B is an illustration of the illumination device using threeoptoelectronic components according to the second exemplary embodimentof the instant disclosure.

FIG. 2C is an illustration of the illumination device applied as a lamptube according to the second exemplary embodiment of the instantdisclosure.

FIG. 2D is an illustration of the illumination device applied as a lampbulb according to the second exemplary embodiment of the instantdisclosure.

FIG. 3A is an illustration of the illumination device using at least oneoptoelectronic component according to the third exemplary embodiment ofthe instant disclosure.

FIG. 3B is an illustration of the illumination device using threeoptoelectronic components according to the third exemplary embodiment ofthe instant disclosure.

FIG. 3C is an illustration of the illumination device applied as a lamptube according to the third exemplary embodiment of the instantdisclosure.

FIG. 3D is an illustration of the illumination device applied as a lampbulb according to the third exemplary embodiment of the instantdisclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the instant disclosure is described in greater detail inconnection with the preferred embodiments, it should be noted thatsimilar elements and structures are designated by like referencenumerals throughout the entire disclosure.

Referring to FIG. 1A, there is the first exemplary embodiment of anillumination device 70 using at least one optoelectronic component 71.The illumination device 70 includes a base 74, the optoelectroniccomponent 71, a first layer 73 (such as an encapsulation layer), and asecond layer 72. In this embodiment, only one optoelectronic component71 is served as a light-emitting module for emitting light, however inalternative embodiment, more than one optoelectronic components 71 asdescribed below also can be adopted as the light-emitting module. Theoptoelectronic component 71 is disposed on the base 74 and electricallyconnected to the base 74 for generating a progressive-typelight-emitting intensity I(θ) decreased gradually from a top surface ofthe optoelectronic component 71 to a peripheral surface of theoptoelectronic component 71. The first layer 73 encapsulates theoptoelectronic component 71, and the second layer 72 encloses the firstlayer 73. The second layer 72 has a progressive-type thickness d(θ)corresponding to the progressive-type light-emitting intensity I(θ),both the progressive-type light-emitting intensity I(θ) and theprogressive-type thickness d(θ) are simultaneously decreased orincreased gradually, i.e. there is a positive correlation between theprogressive-type light-emitting intensity I(θ) and the progressive-typethickness d(θ), thus the progressive-type light-emitting intensity I(θ)generated by the optoelectronic component 71 can be transformed into thesame light-emitting intensity I through the progressive-type thicknessd(θ) of the second layer 72. In other words, the illumination device 70in this embodiment can generate the same light-emitting intensity I bymatching the progressive-type light-emitting intensity I(θ) generated bythe optoelectronic component 71 and the progressive-type thickness d(θ)of the second layer 72.

In this embodiment, the second layer 72 can be disposed above the firstlayer 73. The outline of the first layer 73 may be cambered upwardly toform a semicircle having a cambered outer surface 730, and the shape ofthe outer surface 730 of the first layer 73 can correspond to the shapeof an inner surface (not labeled) of the second layer 72, thus the innersurface of the second layer 72 corresponding to the outer surface 730 ofthe first layer 73 can be inwardly concaved. The optoelectroniccomponent 71 can be disposed directly under a topmost point 7300 of thefirst layer 73, i.e. disposed on a centric position 740 of the base 74.In other words, the topmost point 7300 is a midpoint on the outersurface 730 of the first layer 73 and is equal to a highest point (notlabeled) of the inner surface of the second layer 72. The optoelectroniccomponent 71 may be a LED chip for emitting a monochromatic light, andthe base may be a printed circuit board (PCB), a metal core printedcircuit board (MCPCB), a metal substrate, a glass substrate, or aceramics substrate etc. The first layer 73 may be a transparent, atranslucent layer (such as thermoplastic polymers or thermosettingpolymers), or an air layer etc., and the second layer 72 may be aphosphor layer formed by dispersing a phosphor powder with a pluralityof phosphor particles 720 into polymer resin, such as epoxy or silicone.In addition, the progressive-type light-emitting intensity I(θ)generated by the optoelectronic component 71 can be a function of θdefined by I(θ)=I₀ cos θ, where θ is a light-emitting angle of theoptoelectronic component 71 relative to a vertical center line L, and I₀is a maximum light-emitting intensity generated by the optoelectroniccomponent 71 and usually generated along the vertical center line L ofthe optoelectronic component 71 and corresponding to the topmost point7300 of the first layer 73. The vertical center line L can be defined asan extended line vertically passes through a center point 710 of theoptoelectronic component 71. In this embodiment, the vertical centerline L also passes through the topmost point 7300 of the first layer 73,the highest point of the inner surface of the second layer 72 or thecentric position 740 of the base 74. Because the progressive-typethickness d(θ) divided by the progressive-type light-emitting intensityI(θ) equals a constant number c as shown by

${\frac{d(\theta)}{I(\theta)} = c},$the progressive-type thickness d(θ) of the second layer 72 can be afunction of θ defined by d(θ)=cI₀ cos θ. Hence, if the concentration ofthe phosphor powder in the second layer 72 is substantially uniform andthe particle dimensions of the phosphor particles 720 in the secondlayer 72 are substantially the same, the progressive-type thickness d(θ)of the second layer 72 can be a function of θ defined by d(θ)=cI₀ cos θdue to the definition of

$\frac{d(\theta)}{I(\theta)} = {c.}$Since the second layer 72 may be the phosphor layer having the phosphorpowder with the phosphor particles 720, a first light (not shown) withthe progressive-type light-emitting intensity I(θ) emitted from theoptoelectronic component 71 of the light-emitting module cansequentially pass through the first layer 73 and the second layer 72 togenerate a second light (not shown) with the same light-emittingintensity I after wavelength conversion of the first light.

In other words, when the light-emitting angle θ of the optoelectroniccomponent 71 relative to the vertical center line L is 0 degree, theprogressive-type light-emitting intensity I(θ=0°) generated by theoptoelectronic component 71 as shown by I(0°)=I₀ cos 0°=I₀ cancorrespond to the progressive-type thickness d(θ=0°) of the second layer72 as shown by) d(0°). When the light-emitting angle θ of theoptoelectronic component 71 relative to the vertical center line L isθ₁, the progressive-type light-emitting intensity I(θ=θ₁) generated bythe optoelectronic component 71 as shown by I(θ₁)=I₀ cos θ₁ cancorrespond to the progressive-type thickness d(θ=θ₁) of the second layer72 as shown by d(θ₁). When the light-emitting angle θ of theoptoelectronic component 71 relative to the vertical center line L isθ₂, the progressive-type light-emitting intensity I(θ=θ₂) generated bythe optoelectronic component 71 as shown by I(θ₂)=I₀ cos θ₂ cancorrespond to the progressive-type thickness d(θ=θ₂) of the second layer72 as shown by d(θ₂). Furthermore, the above description here is theillustration between the light-emitting intensity I(θ) of theoptoelectronic component 71 and the progressive-type thickness d(θ) ofthe second layer 72 on one side area (such as the left half area)relative to the vertical center line L, but there is the samerelationship between the light-emitting intensity I(θ) of theoptoelectronic component 71 and the progressive-type thickness d(θ) ofthe second layer 72 on another side area (such as the right half area)relative to the vertical center line L.

Therefore, when the light-emitting angle θ of the optoelectroniccomponent 71 is increased gradually such as 0°<θ₁<θ₂, theprogressive-type light-emitting intensity I(θ) generated by theoptoelectronic component 71 is decreased gradually such as I₀>I₀ cosθ₁>I₀ cos θ₂, thus the optoelectronic component 71 cannot provide auniform light-emitting source due to different light-emitting angles θof the optoelectronic component 71. However, when the first layer 73 isdisposed under the second layer 72, the progressive-type thickness d(θ)of the second layer 72 decreased gradually such as d(0°)>d(θ₁)>d(θ₂) cancorrespond to the progressive-type light-emitting intensity I(θ)generated by the optoelectronic component 71 decreased gradually such asI₀>I₀ cos θ₁>I₀ cos θ₂, thus the progressive-type light-emittingintensity I(θ) generated by the optoelectronic component 71 can betransformed into the same light-emitting intensity I through theprogressive-type thickness d(θ) of the second layer 72. In other words,when both the progressive-type light-emitting intensity I(θ) generatedby the optoelectronic component 71 and the progressive-type thicknessd(θ) of the second layer 72 are simultaneously decreased graduallyaccording to the increasing light-emitting angle θ of the optoelectroniccomponent 71, the progressive-type thickness d(θ) divided by theprogressive-type light-emitting intensity I(θ) can equal to a constantnumber c as shown by

${\frac{d(\theta)}{I(\theta)} = c},$thus the progressive-type light-emitting intensity I(θ) generated by theoptoelectronic component 71 can be transformed into the samelight-emitting intensity I through the progressive-type thickness d(θ)of the second layer 72. Hence, the illumination device 70 in thisembodiment can provide a uniform light-emitting source by using theprogressive-type thickness d(θ) of the second layer 72.

Referring to FIG. 1B, it shows an illumination device 70 using aplurality of optoelectronic components 71. In this embodiment, theillumination device 70 includes a base 74, three optoelectroniccomponents 71, a first layer 73, and a second layer 72. Similar to theabove description, the three optoelectronic components 71 are served asthe light-emitting module for emitting light and can be covered with thefirst layer 73, and the first layer 73 can be covered with the secondlayer 72. Further, the arrangement of the optoelectronic components 71on the base 74 in this embodiment is merely an example and is not meantto limit the instant disclosure.

Referring to FIG. 1C, it shows the illumination device using at leastone offset optoelectronic component. There is an imaginaryoptoelectronic component 71′ imaginatively disposed on the centricposition 740 of the base 74 and directly under the topmost point 7300 ofthe first layer 73 or under the highest point of the inner surface ofthe second layer 72 as shown in FIGS. 1A and 1B, and when anoptoelectronic components 71 is separated from the imaginaryoptoelectronic component 71′ by a horizontal offset distance {rightarrow over (a)}, the progressive-type light-emitting intensity I(r′,θ′)generated by the optoelectronic component 71 is a function of r′ andθ′defined by

${{I\left( {r^{\prime},\theta^{\prime}} \right)} = {\frac{I_{0}}{r^{\prime}}\cos\;\theta^{\prime}}},$where θ′ is a light-emitting angle of the optoelectronic component 71relative to its vertical center line L′, I₀ is a maximum light-emittingintensity generated by the imaginary optoelectronic component 71′, andr′ is a radius between the optoelectronic component 71 and the outersurface 730 of the first layer 73. Moreover, the trigonometric functionrelationship between θ, θ′, r, r′, and {right arrow over (a)} can bedefined by r sin θ−{right arrow over (a)}=r′ sin θ′, r cos θ=r′ cos θ′,and r′²=r²+a²−2r{right arrow over (a)} sin θ, where θ is alight-emitting angle of the imaginary optoelectronic component 71′relative to a vertical center line L that can vertically pass through acenter point 710′ of the imaginary optoelectronic component 71′, and ris a radius of the first layer 73. Hence, the progressive-typelight-emitting intensity I(r′,θ′) generated by the optoelectroniccomponent 71 defined by

${I\left( {r^{\prime},\theta^{\prime}} \right)} = {\frac{I_{0}}{r^{\prime}}\cos\;\theta^{\prime}}$can be substantially transmitted into the progressive-typelight-emitting intensity I(θ) generated by the optoelectronic component71 defined by

${{I(\theta)} = {{\frac{I_{0}r}{r^{\prime 2}}\cos\;\theta} = {\frac{I_{0}}{r}\cos\;{\theta\left( {1 + \frac{{\overset{\rightarrow}{a}}^{2}}{r^{2}} - {2\frac{\overset{\rightarrow}{a}}{r}\sin\;\theta}} \right)}^{- 1}}}},$thus the progressive-type light-emitting intensity I(r′,θ′) generated bythe optoelectronic component 71 can approximate to the progressive-typelight-emitting intensity I(θ) generated by the optoelectronic component71, i.e. shown by I(r′,θ′)≡I(θ).

Referring to FIGS. 1B and 1C, because the progressive-typelight-emitting intensity I(θ) generated by any one of the threeoptoelectronic components 71 can be a function of θ defined by

${{I(\theta)} = {{\frac{I_{0}r}{r^{\prime 2}}\cos\;\theta} = {\frac{I_{0}}{r}\cos\;{\theta\left( {1 + \frac{{\overset{\rightarrow}{a}}^{2}}{r^{2}} - {2\frac{\overset{\rightarrow}{a}}{r}\sin\;\theta}} \right)}^{- 1}}}},$thus the progressive-type light-emitting intensity I(θ) generated by thelight-emitting module including the three optoelectronic components 71can be a function of θ defined by

${{I(\theta)} = {{\sum\limits_{i}{I_{i}(\theta)}} = {\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}}}},$wherein i is the amount of the optoelectronic components 71, {rightarrow over (a)}_(i) is a horizontal offset distance between the centerpoint 710 of each corresponding optoelectronic component 71 and thecenter point 710′ of the imaginary optoelectronic component 71′ that isimaginatively disposed on the centric position 740 of the base 74 anddirectly under the topmost point 7300 of the first layer 73 or thehighest point of the inner surface of the second layer 72 as shown inFIG. 1B, θ is a light-emitting angle of the imaginary optoelectroniccomponent 71′ relative to a vertical center line L that can verticallypass through the center point 710′ of the imaginary optoelectroniccomponent 71′, I₀ is a maximum light-emitting intensity generated by theimaginary optoelectronic component 71′, and r is a radius of the firstlayer 73. For example, when the amount of the optoelectronic components71 (i) is three, the horizontal offset distance ({right arrow over(a)}_(i)) between the center point 710 of each correspondingoptoelectronic component 71 and the center point 710′ of the imaginaryoptoelectronic component 71′ can be defined by {right arrow over (a)}₁,{right arrow over (a)}₂, and {right arrow over (a)}₃ as shown in FIG.1B, where {right arrow over (a)}₁ can be equal to zero ({right arrowover (a)}₁=0) or larger than zero, and {right arrow over (a)}₂ and{right arrow over (a)}₃ can be the same or different according todifferent design requirements. Because the progressive-type thicknessd(θ) divided by the progressive-type light-emitting intensity I(θ)equals a constant number c as shown by

${\frac{d(\theta)}{I(\theta)} = c},$the progressive-type thickness d(θ) of the second layer 72 can be afunction of θ defined by

${{d(\theta)} = {c\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}}},$thus the progressive-type light-emitting intensity I(θ) generated by thelight-emitting module can be transformed into the same light-emittingintensity I through the progressive-type thickness d(θ) of the secondlayer 72.

Furthermore, the illumination device 70 can further include a holdermodule that may be a tube holder 75 (as shown in FIG. 1D) or a bulbholder 76 (as shown in FIG. 1E) as a support structure for supportingthe base 74. Referring to FIGS. 1D and 1E, the second layer 72 can beseparated from the first layer 73 to form an air layer A between thefirst layer 73 and the second layer 72. In FIG. 1D, the first layer 73can be a single encapsulation layer to encapsulate three optoelectroniccomponents 71. In FIG. 1E, the first layer 73 having a plurality ofencapsulating units 73 a used to respectively encapsulate respectiveoptoelectronic components 71. The thickness of the second layer 72 ofthe illumination device 70 still has the same relationship as describedabove. Of course, the type of holder module in FIG. 1D or FIG. 1E can bechanged into another type. In alternative embodiment, the structure ofencapsulating the optoelectronic components 71 with the first layer 73in FIG. 1D can be replaced by another structure of respectivelyencapsulating the optoelectronic components 71 with respectiveencapsulating units 73 a in FIG. 1E, or the structure of respectivelyencapsulating the optoelectronic components 71 with respectiveencapsulating units 73 a in FIG. 1E can be replaced by another structureof encapsulating the optoelectronic components 71 with the first layer73 in FIG. 1D. In other words, the illumination device 70 can be used asa lamp tube or a lamp bulb for providing a uniform light-emitting sourcehaving the same light-emitting intensity.

Referring to FIG. 2A, it shows the second exemplary embodiment of anillumination device 80 using at least one optoelectronic component 81.The illumination device 80 of the second embodiment is similar to theillumination device 70 of the first embodiment. However, the differencetherebetween is that: the second layer 82 in this embodiment has aprogressive-type concentration D(θ) of the phosphor powder rather thanthe progressive-type thickness d(θ) as described above. Theprogressive-type concentration D(θ) is corresponding to theprogressive-type light-emitting intensity I(θ), both theprogressive-type light-emitting intensity I(θ) and the progressive-typeconcentration D(θ) are simultaneously decreased or increased gradually,i.e. there is a positive correlation between the progressive-typelight-emitting intensity I(θ) and the progressive-type concentrationD(θ), thus the progressive-type light-emitting intensity I(θ) generatedby the optoelectronic component 81 can be transformed into the samelight-emitting intensity I through the progressive-type concentrationD(θ) of the phosphor powder in the second layer 82. In other words, theillumination device 80 in this embodiment can generate the samelight-emitting intensity I by matching the progressive-typelight-emitting intensity I(θ) generated by the optoelectronic component81 and the progressive-type concentration D(θ) of the phosphor powder inthe second layer 82.

Similar to the above-mentioned deduction, the progressive-typeconcentration D(θ) of the phosphor powder divided by theprogressive-type light-emitting intensity I(θ) equals a constant numberc as shown by

${\frac{D(\theta)}{I(\theta)} = c},$the progressive-type concentration D(θ) of the phosphor powder in thesecond layer 82 can be a function of θ defined by D(θ)=cI₀ cos θ. Hence,if the thickness of the second layer 82 is substantially the same andthe particle dimensions of the phosphor particles 820 in the secondlayer 82 are substantially the same, the progressive-type concentrationD(θ) of the phosphor powder in the second layer 82 can be a function ofθ defined by D(θ)=cI₀ cos θ due to the definition of

$\frac{D(\theta)}{I(\theta)} = {c.}$Since the second layer 82 contains the phosphor powder with a pluralityof phosphor particles 820, a first light (not shown) with theprogressive-type light-emitting intensity I(θ) emitted from theoptoelectronic component 81 of the light-emitting module cansequentially pass through the first layer 83 and the second layer 82 togenerate a second light (not shown) with the same light-emittingintensity I after wavelength conversion of the first light.

Similarly, when the light-emitting angle θ of the optoelectroniccomponent 81 relative to the vertical center line L is 0 degree, theprogressive-type light-emitting intensity I(θ=0° generated by theoptoelectronic component 81 as shown by I(0°)=I₀ cos 0°=I₀ cancorrespond to the progressive-type concentration D(θ=0°) of the phosphorpowder in the second layer 82 as shown by D(0°). When the light-emittingangle θ of the optoelectronic component 81 relative to the verticalcenter line L is θ₁, the progressive-type light-emitting intensityI(θ=θ₁) generated by the optoelectronic component 81 as shown byI(θ₁)=I₀ cos θ₁, can correspond to the progressive-type concentrationD(θ=θ₁) as shown by D(θ₁). When the light-emitting angle θ of theoptoelectronic component 81 relative to the vertical center line L isθ₂, the progressive-type light-emitting intensity I(θ=θ₂) generated bythe optoelectronic component 81 as shown by I(θ₂)=I₀ cos θ₂ cancorrespond to the progressive-type concentration D(θ=θ₂) as shown byD(θ₂).

Therefore, when the light-emitting angle θ is increased gradually suchas 0°<θ₁<θ₂, the progressive-type light-emitting intensity I(θ) isdecreased gradually such as I₀>I₀ cos θ₁>I₀ cos θ₂, thus theoptoelectronic component 81 cannot provide a uniform light-emittingsource due to different light-emitting angles θ of the optoelectroniccomponent 81. However, when the first layer 83 is covered with thesecond layer 82, the progressive-type concentration D(θ) decreasedgradually such as D (0°)>D(θ₁)>D (θ₂) can correspond to theprogressive-type light-emitting intensity I(θ) decreased gradually suchas I₀>I₀ cos θ₁>I₀ cos θ₂, thus the progressive-type light-emittingintensity I(θ) can be transformed into the same light-emitting intensityI through the progressive-type concentration D(θ). In other words, whenboth the progressive-type light-emitting intensity I(θ) and theprogressive-type concentration D(θ) are simultaneously decreasedgradually according to the increasing light-emitting angle θ of theoptoelectronic component 81 and the function of

${\frac{D(\theta)}{I(\theta)} = c},$thus the progressive-type light-emitting intensity I(θ) generated by theoptoelectronic component 81 can be transformed into the samelight-emitting intensity I through the progressive-type concentrationD(θ) of the phosphor powder in the second layer 82. Hence, theillumination device 80 can provide a uniform light-emitting source byusing the progressive-type concentration D(θ) of the phosphor powder inthe second layer 82.

Referring to FIG. 2B, it shows an illumination device 80 using aplurality of optoelectronic components 81. The illumination device 80 inFIG. 2B is similar to the illumination device 70 in FIG. 1A and includesa base 84, three optoelectronic components 81, a first layer 83, and asecond layer 82. Similar to the above description, the threeoptoelectronic components 81 are served as the light-emitting module foremitting light and can be covered with the first layer 83, and the firstlayer 83 can be covered with the second layer 82. Further, thearrangement of the optoelectronic components 81 on the base 84 in thisembodiment is merely an example and is not meant to limit the instantdisclosure.

Referring to FIGS. 2B and 1C, because the progressive-typelight-emitting intensity I(θ) generated by any one of the threeoptoelectronic components 81 can be a function of θ defined by

${I(\theta)} = {{\frac{I_{0}r}{r^{\prime 2}}\cos\;\theta} = {\frac{I_{0}}{r}\cos\;{\theta\left( {1 + \frac{{\overset{\rightarrow}{a}}^{2}}{r^{2}} - {2\frac{\overset{\rightarrow}{a}}{r}\sin\;\theta}} \right)}^{- 1}}}$the same as the first embodiment, thus the progressive-typelight-emitting intensity I(θ) generated by the light-emitting moduleincluding the three optoelectronic components 81 can be a function of θdefined by

${{I(\theta)} = {{\sum\limits_{i}{I_{i}(\theta)}} = {\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}}}},$wherein i is the amount of the optoelectronic components 81, {rightarrow over (a)}_(i) is a horizontal offset distance between the centerpoint 810 of each corresponding optoelectronic component 81 and thecenter point 810′ of the imaginary optoelectronic component 81′ that isimaginatively disposed on a centric position 840 of the base 84, θ is alight-emitting angle of the imaginary optoelectronic component 81′relative to a vertical center line L of the imaginary optoelectroniccomponent 81′, I₀ is a maximum light-emitting intensity generated by theimaginary optoelectronic component 81′, and r is a radius of the firstlayer 83. Similar to the first embodiment, three optoelectroniccomponents 81 have respective horizontal offset distances {right arrowover (a)}₁, {right arrow over (a)}₂, and {right arrow over (a)}₃, asshown in FIG. 2B. Because of the definition of

${\frac{D(\theta)}{I(\theta)} = c},$the progressive-type concentration D(θ) of the phosphor powder in thesecond layer 82 can be a function of θ defined by

${{D(\theta)} = {c\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}}},$thus the progressive-type light-emitting intensity I(θ) generated by thelight-emitting module can be transformed into the same light-emittingintensity I through the progressive-type concentration D(θ) of thephosphor powder in the second layer 82.

Furthermore, the illumination device 80 can further include a holdermodule that may be a tube holder 85 (as shown in FIG. 2C) or a bulbholder 86 (as shown in FIG. 2D) as a support structure for supportingthe base 84. Referring to FIGS. 2C and 2D, the second layer 82 can beseparated from the first layer 83 to form an air layer A between thefirst layer 83 and the second layer 82. In FIG. 2C, the first layer 83can be a single encapsulation layer to encapsulate three optoelectroniccomponents 81. In FIG. 2D, the first layer 83 having a plurality ofencapsulating units 83 a used to respectively encapsulate respectiveoptoelectronic components 81. The concentration of the second layer 82of the illumination device 80 still has the same relationship asdescribed above. Of course, the type of holder module in FIG. 2C or FIG.2D can be changed into another type. In alternative embodiment, thestructure of encapsulating the optoelectronic components 81 with thefirst layer 83 in FIG. 2C can be replaced by another structure ofrespectively encapsulating the optoelectronic components 81 withrespective encapsulating units 83 a in FIG. 2D, or the structure ofrespectively encapsulating the optoelectronic components 81 withrespective encapsulating units 83 a in FIG. 2D can be replaced byanother structure of encapsulating the optoelectronic components 81 withthe first layer 83 in FIG. 2C. In other words, the illumination device80 can be used as a lamp tube or a lamp bulb for providing a uniformlight-emitting source having the same light-emitting intensity.

Referring to FIG. 3A, its shows the third exemplary embodiment of anillumination device 90 using at least one optoelectronic component 91.The illumination device 90 of the third embodiment is similar to theillumination device 70 or 80 in the first or second embodiment. However,the difference therebetween is that: the second layer 92 in thisembodiment has a progressive-type particle radius R(θ) of the phosphorpowder rather than the progressive-type thickness d(θ) or theprogressive-type concentration D(θ) as described above. Theprogressive-type particle radius R(θ) can correlate with theprogressive-type light-emitting intensity I(θ), the progressive-typelight-emitting intensity I(θ) can be decreased or increased gradually,the progressive-type particle radius R(θ) of the phosphor powder can bedecreased or increased gradually, and the progressive-typelight-emitting intensity I(θ) can be varied inversely as theprogressive-type particle radius R(θ) of the phosphor powder, i.e. thereis a negative correlation between the progressive-type light-emittingintensity I(θ) and the progressive-type particle radius R(θ), thus theprogressive-type light-emitting intensity I(θ) generated by theoptoelectronic component 91 can be transformed into the samelight-emitting intensity I through the progressive-type particle radiusR(θ) of the phosphor powder in the second layer 92. In other words, theillumination device 90 of the instant disclosure can generate the samelight-emitting intensity I by matching the progressive-typelight-emitting intensity I(θ) generated by the optoelectronic component91 and the progressive-type particle radius R(θ) of the phosphor powderin the second layer 92.

Similar to the above-mentioned deduction, the progressive-type particleradius R(θ) multiplied by the progressive-type light-emitting intensityI(θ) equals a constant number c as shown by R(θ)*I(θ)=c, theprogressive-type particle radius R(θ) can be a function of θ defined by

${R(\theta)} = {\frac{c}{I_{0}\cos\;\theta}.}$Of course, because the total volume V of the whole phosphor particles920 can be defined by V=N*4/3πR³, where N is the amount of the phosphorparticles 920 and R is a radius of the phosphor particle 920, thus it isvery clear to know that the total surface area S of the phosphorparticles 920 can be defined by S=N*4πR²=3V/R∝1/R, and

${R(\theta)} = {\frac{c}{I(\theta)} = \frac{c}{I_{0}\cos\;\theta}}$is obtained due to the definition of

$\frac{S(\theta)}{I(\theta)} = {c.}$Hence, if the concentration of the phosphor powder in the second layer92 is substantially uniform and the thickness of the second layer 92 issubstantially the same, the progressive-type particle radius R(θ) of thephosphor powder in the second layer 92 can be a function of θ defined by

${R(\theta)} = \frac{c}{I_{0}\cos\;\theta}$due to the definition of R(θ)*I(θ)=c. Since the second layer 92 is thephosphor layer, a first light (not shown) with the progressive-typelight-emitting intensity I(θ) emitted from the optoelectronic component91 of the light-emitting module can sequentially pass through the firstlayer 93 and the second layer 92 to generate a second light (not shown)with the same light-emitting intensity I after wavelength conversion ofthe first light.

Similarly, when the light-emitting angle θ of the optoelectroniccomponent 91 relative to the vertical center line L is 0 degree, theprogressive-type light-emitting intensity I(θ=0°) generated by theoptoelectronic component 91 as shown by I(0°)=I₀ cos 0°=I₀ cancorrespond to the progressive-type particle radius R(θ=0°) of thephosphor powder in the second layer 92 as shown by R(0°). When thelight-emitting angle θ of the optoelectronic component 91 relative tothe vertical center line L is θ₁, the progressive-type light-emittingintensity I(θ=θ₁) generated by the optoelectronic component 91 as shownby I(θ₁)=I₀ cos θ₁ can correspond to the progressive-type particleradius R(θ=θ₁) as shown by R(θ₁). When the light-emitting angle θ of theoptoelectronic component 91 relative to the vertical center line L isθ₂, the progressive-type light-emitting intensity I(θ=θ₂) generated bythe optoelectronic component 91 as shown by I(θ₂)=I₀ cos θ₂ cancorrespond to the progressive-type particle radius R(θ=θ₂) as shown byR(θ₂).

Therefore, when the light-emitting angle θ is increased gradually suchas 0°<θ₁<θ₂, the progressive-type light-emitting intensity I(θ) isdecreased gradually such as I₀>I₀ cos θ₁>I₀ cos θ₂, thus theoptoelectronic component 91 cannot provide a uniform light-emittingsource due to different light-emitting angles θ of the optoelectroniccomponent 91. However, when the first layer 93 is covered with thesecond layer 92, the progressive-type particle radius R(θ) increasedgradually such as R(0°)<R(θ₁)<R(θ₂) can correspond to theprogressive-type light-emitting intensity I(θ) decreased gradually suchas I₀>I₀ cos θ₁>I₀ cos θ₂, thus the progressive-type light-emittingintensity I(θ) can be transformed into the same light-emitting intensityI through the progressive-type particle radius R(θ). In other words,when the progressive-type light-emitting intensity I(θ) and theprogressive-type particle radius R(θ) are respectively decreased andincreased gradually according to the increasing light-emitting angle θof the optoelectronic component 91, the progressive-type particle radiusR(θ) multiplied by the progressive-type light-emitting intensity I(θ)can equal to a constant number c as shown by R(θ)*I(θ)=c, thus theprogressive-type light-emitting intensity I(θ) generated by theoptoelectronic component 91 can be transformed into the samelight-emitting intensity I through the progressive-type particle radiusR(θ) of the phosphor powder in the second layer 92. Hence, theillumination device 90 can provide a uniform light-emitting source byusing the progressive-type particle radius R(θ) of the phosphor powderin the second layer 92.

Referring to FIG. 3B, it shows an illumination device 90 using aplurality of optoelectronic components according to the instantdisclosure. The illumination device 90 in FIG. 3B is similar to theillumination device 70 in FIG. 1A or the illumination device 80 in FIG.2A and includes a base 94, three optoelectronic components 91, a firstlayer 93, and a second layer 92. Similar to the above description, thethree optoelectronic components 91 are served as the light-emittingmodule for emitting light and can be covered with the first layer 93,and the first layer 93 can be covered with the second layer 92.

Referring to FIGS. 3B and 1C, because the progressive-typelight-emitting intensity I(θ) generated by any one of the threeoptoelectronic components 91 can be a function of θ defined by

${I(\theta)} = {{\frac{I_{0}r}{r^{\prime 2}}\cos\;\theta} = {\frac{I_{0}}{r}\cos\;{\theta\left( {1 + \frac{{\overset{\rightarrow}{a}}^{2}}{r^{2}} - {2\frac{\overset{\rightarrow}{a}}{r}\sin\;\theta}} \right)}^{- 1}}}$the same as the first embodiment, thus the progressive-typelight-emitting intensity I(θ) generated by the light-emitting moduleincluding the three optoelectronic components 91 can be a function of θdefined by

${{I(\theta)} = {{\sum\limits_{i}{I_{i}(\theta)}} = {\frac{I_{0}}{r}\cos\;{\theta\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)}^{- 1}}}},$wherein i is the amount of the optoelectronic components 91, {rightarrow over (a)}_(i) is a horizontal offset distance between the centerpoint 910 of each corresponding optoelectronic component 91 and thecenter point 910′ of the imaginary optoelectronic component 91′ that isimaginatively disposed on a centric position 940 of the base 94, θ is alight-emitting angle of the imaginary optoelectronic component 91′relative to a vertical center line L of the imaginary optoelectroniccomponent 91′, I₀ is a maximum light-emitting intensity generated by theimaginary optoelectronic component 91′, and r is a radius of the firstlayer 93. Similar to the first embodiment, three optoelectroniccomponents 91 have respective horizontal offset distances {right arrowover (a)}₁, {right arrow over (a)}₂, and {right arrow over (a)}₃ asshown in FIG. 3B. Because of the definition of R(θ)*I(θ)=c, theprogressive-type particle radius R(θ) of the phosphor powder in thesecond layer 92 can be a function of θ defined by

${{R(\theta)} = {c\left\lbrack {\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}} \right\rbrack}^{- 1}},$thus the progressive-type light-emitting intensity I(θ) generated by thelight-emitting module can be transformed into the same light-emittingintensity I through the progressive-type particle radius R(θ) of thephosphor powder in the second layer 92.

Furthermore, the illumination device 90 can further include a holdermodule that may be a tube holder 95 (as shown in FIG. 3C) or a bulbholder 96 (as shown in FIG. 3D) as a support structure for supportingthe base 94. Referring to FIGS. 3C and 3D, the second layer 92 can beseparated from the first layer 93 to form an air layer A between thefirst layer 93 and the second layer 92. In FIG. 3C, the first layer 93can be a single encapsulation layer to encapsulate three optoelectroniccomponents 91. In FIG. 3D, the first layer 93 having a plurality ofencapsulating units 93 a used to respectively encapsulate respectiveoptoelectronic components 91. The particle radius of the second layer 92of the illumination device 90 still has the same relationship asdescribed above. Of course, the type of holder module in FIG. 3C or FIG.3D can be changed into another type. In alternative embodiment, thestructure of encapsulating the optoelectronic components 91 with thefirst layer 93 in FIG. 3C can be replaced by another structure ofrespectively encapsulating the optoelectronic components 91 withrespective encapsulating units 93 a in FIG. 3D, or the structure ofrespectively encapsulating the optoelectronic components 91 withrespective encapsulating units 93 a in FIG. 3D can be replaced byanother structure of encapsulating the optoelectronic components 91 withthe first layer 93 in FIG. 3C. In other words, the illumination device90 can be used as a lamp tube or a lamp bulb for providing a uniformlight-emitting source having the same light-emitting intensity.

In conclusion, when the light-emitting module including at least one ormore than two optoelectronic components (71, 81, or 91) disposed on thebase (74, 84, or 94) for generating a first light having aprogressive-type light-emitting intensity I(θ), the second layer (72,82, or 92) such as a phosphor layer has a progressive-type structure incorrelation with the progressive-type light-emitting intensity I(θ),thus the first light emitted from the light-emitting module can passthrough the second layer (72, 82, or 92) to generate a second lighthaving the same light-emitting intensity I. For example, theprogressive-type structure may be one of a progressive-type thicknessd(θ), a progressive-type concentration D(θ) of the phosphor powder, anda progressive-type particle radius R(θ) of the phosphor powder.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention.

1. An illumination device, comprising: a base; a light-emitting moduledisposed on the base for generating a progressive-type light-emittingintensity; a first layer encapsulating the light-emitting module; and asecond layer enclosing the first layer, wherein the second layer has aprogressive-type thickness corresponding to the progressive-typelight-emitting intensity, both the progressive-type light-emittingintensity and the progressive-type thickness are decreased or increasedgradually, and the progressive-type light-emitting intensity istransformed into the same light-emitting intensity through theprogressive-type thickness of the second layer.
 2. The illuminationdevice of claim 1, wherein the light-emitting module includes at leastone optoelectronic component disposed on a centric position of the base,the progressive-type light-emitting intensity generated by the at leastone optoelectronic component is a function of θ defined by I(θ)=I₀ cosθ, and the progressive-type thickness of the second layer is a functionof θ defined by d(θ)=cI₀ cos θ, wherein θ is a light-emitting angle ofthe at least one optoelectronic component relative to a vertical centerline vertically passing through a center point of the at least oneoptoelectronic component, I₀ is a maximum light-emitting intensitygenerated by the at least one optoelectronic component, and c is aconstant number.
 3. The illumination device of claim 2, wherein the atleast one optoelectronic component is covered with the first layer, andthe first layer is covered with the second layer, wherein the firstlayer is one of a transparent layer, a translucent layer, and an airlayer, and the second layer is a phosphor layer formed by dispersing aphosphor powder with a plurality of phosphor particles into polymerresin.
 4. The illumination device of claim 2, further comprising: aholder module being one of a tube holder and a bulb holder forsupporting the base, wherein the at least one optoelectronic componentis covered with the first layer, the second layer is separated from thefirst layer to form an air layer between the first layer and the secondlayer, and the second layer is a phosphor layer having a phosphor powderwith a plurality of phosphor particles.
 5. The illumination device ofclaim 1, wherein the light-emitting module includes a plurality ofoptoelectronic components disposed on the base, the progressive-typelight-emitting intensity generated by the light-emitting module is afunction of θ defined by${{I(\theta)} = {{\sum\limits_{i}{I_{i}(\theta)}} = {\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}}}},$and the progressive-type thickness of the second layer is a function ofθ defined by${{d(\theta)} = {c\frac{I_{0}}{r}\cos\;\theta{\sum\limits_{i}\left( {1 + \frac{{\overset{\rightarrow}{a}}_{i}^{2}}{r^{2}} - {2\frac{{\overset{\rightarrow}{a}}_{i}}{r}\sin\;\theta}} \right)^{- 1}}}},$wherein i is the amount of the optoelectronic components, {right arrowover (a)}_(i) is a horizontal offset distance between a center point ofeach corresponding optoelectronic component and a center point of animaginary optoelectronic component that is imaginatively disposed on acentric position of the base, θ is a light-emitting angle of theimaginary optoelectronic component relative to a vertical center linevertically passing through a center point of the imaginaryoptoelectronic component, I₀ is a maximum light-emitting intensitygenerated by the imaginary optoelectronic component, r is a radius ofthe first layer, and c is a constant number.
 6. The illumination deviceof claim 5, wherein the optoelectronic components are covered with thefirst layer or respectively covered with a plurality of encapsulatingunits of the first layer, and the first layer is covered with the secondlayer, wherein the first layer is one of a transparent layer, atranslucent layer, and an air layer, and the second layer is a phosphorlayer having a phosphor powder with a plurality of phosphor particles.7. The illumination device of claim 5, further comprising: a holdermodule being one of a tube holder and a bulb holder for supporting thebase, wherein the optoelectronic components are covered with the firstlayer or respectively covered with a plurality of encapsulating units ofthe first layer, and the second layer is separated from the first layerto form an air layer between the first layer and the second layer, andthe second layer is a phosphor layer formed by mixing a phosphor powderhaving a plurality of phosphor particles with polymer resin.